The present disclosure relates to the subject matter disclosed in German application No. 10160 452.1 of Dec. 4, 2001, which is incorporated herein by reference in its entirety and for all purposes.
The invention relates to a code carrier device for mounting on a material flow object, with a code carrier, which comprises a memory for storing an individual identification and a transmitter device for transmitting the identification, so that the identification can be contactlessly read by a receiver when the transmitter device and receiver are in a specific relative positional range in relation to each other.
Code carriers, such as transponders for example, are used to provide specific objects with an xe2x80x9cunlosablexe2x80x9d identification which can be contactlessly read and, if appropriate, written. For example, material flow objects such as pallets on an assembly line are provided with corresponding code carrier devices, to allow the content of the pallets to be contactlessly read electronically without having to stop the material flow, for example on an assembly line.
The present invention provides a code carrier device with which an identification of a material flow object can be read in a simple way. In accordance with the present invention, the transmitter device has a first transmitting face and at least a second transmitting face, being transversely thereto, by means of which the identification can in each case be read, the readability being determined by the relative position between a receiver and a transmitting face.
The fact that there are at least two transmitting faces allows the identification to be read with respect to at least two transversely disposed directions of movement of the material flow object. This allows that, with appropriate receivers, in particular receivers positioned in a fixed place, the identification can be read even if the material flow object changes its direction of movement; in particular, the at least two transmitting faces are in this case adapted to the possible directions of movement of the material flow object, that is to say the identification can be read via one transmitting face when there is movement of the material flow object in one specific direction and the identification can be read via the other transmitting face when there is movement in a direction transverse thereto.
A transmitting face is in this case an effective transmitting face via which an antenna of the transmitter device radiates signals which contain the identification.
In particular, a first energy flux density vector (Poynting vector) of the radiation, relative to the first transmitting face, and a second energy flux density vector, relative to the second transmitting face, which is in the same relationship with the second transmitting face as the first energy flux density vector is with the first transmitting face, are transversely in relation to each other. This means that the first transmitting face and the at least one further transmitting face have substantially the same radiation characteristic.
As a result, a receiver which is intended, for example, to read an identification when there is a transverse movement of the material flow object can then be positioned in the same way as a corresponding receiver which is intended to read the identification when there is a movement of the material flow object in a first direction.
A code carrier device can be produced in a simple and low-cost way if a transmitter of the transmitter device which forms a transmitting face comprises a coil. Such a transmitter or transponder can be inductively induced by means of a receiver, the receiver then at the same time supplying the energy which is in turn required for transmitting the identification.
It is advantageous if a transmitter comprises a toroidal coil. A toroidal coil can be produced at low cost and can also be arranged in a housing in a simple way in technical terms of production. Furthermore, a receiver may then also comprise a toroidal coil. If two toroidal coils are arranged parallel to each other, the field permeation is particularly great. As a result, the appropriate identification can be read from a code carrier in a simple and reliable way even at relatively great distances. In addition, it is also possible to use pot core halves for such toroidal coils, so that the latter can also be installed in steel.
In particular, an energy flux density associated with a transmitting face is free from nodes, so that a good radiation characteristic is accomplished, at least with respect to a half-space.
The transmitter device is advantageously arranged in a housing. In this respect, on the one hand said device is protected from external influences and on the other hand the transmitter device can then be attached to a material flow object in a specifically aligned manner.
In particular, the first transmitting face is arranged with respect to a first lateral face of the housing and the second transmitting face is arranged with respect to a second lateral face, which is transversely in relation to the first lateral face. As a result, the transmitter device is positioned in the housing with its transmitting faces specifically directed and, by appropriate positioning of the housing on the material flow object, these transmitting faces can in turn be aligned with respect to the directions of movement of the material flow object, so that, when appropriately mounted on the material flow object, it is possible to set the readability of the identification in such a way that it depends on the direction of movement of the material flow object.
In particular, it is then advantageous if a transmitting face is oriented substantially parallel to a lateral face, in order in this way to minimize the space requirement of the housing.
Furthermore, it is advantageous if the first lateral face and the second lateral face have a common edge. This allows the identification to be read when the material flow object is moving in the first direction or in a direction transverse thereto.
It is advantageous if transmitting faces being transversely in relation to each other are formed by different transmitters of the transmitter device. This allows, for example, the effect to be achieved that, to read an identification, the transmitter and receiver can be positioned with their respective transmitting faces and receiving faces parallel to each other and this parallel positionability with optimized response sensitivity is in this case independent of the direction of movement of the material flow object.
In the case of a variant of an embodiment, to provide the transmitting faces, the transmitter device comprises coils connected parallel. This makes it possible to achieve a situation in which only the coil activated by a receiver radiates, while the other coil, with the transmitting face oriented transversely thereto, does not radiate.
However, it may also be provided that, to provide the transmitting faces, the transmitter device comprises coils connected in series.
If one coil is then activated by means of a receiver, both coils radiate the corresponding identification. This can be used, for example, to carry out a deflection of the direction of movement of the material flow object: if a receiver which is appropriately arranged senses a signal of the transversely lying transmitting face, that is to say the transmitting face which lies transversely in relation to the direction of movement of the material flow object at that moment (with a direction of the normal parallel to this direction of movement), a deflection of the material flow object to its transverse direction of movement can then be initiated as a result.
It may also be provided that a capacitor is connected in series with the coils. This allows the specifically set resonance step-up to be used to amplify the corresponding transmission signal.
It may alternatively be provided that the transversely lying transmitting faces of the transmitter device are provided by a single transmitter and, in particular, the transmitter comprises a bar coil, which is arranged in such a way that it has the same radiation characteristic transversely in relation to a first direction of movement of the material flow object as transversely in relation to a second direction of movement of the material flow object, the first and second directions of movement being transverse to each other. In particular, this bar coil is in this case arranged in a corner of a housing, this corner in turn being aligned with a corner of the material flow object.
A relative position between the transmitter device and the receiver for reading the identification is determined by a linear spacing and a transverse spacing between a transmitting face and the receiver. If code carrier devices and receivers are too far apart, in terms of both the linear spacing and the transverse spacing, the receiver cannot activate the transmitter and, as a result, the transmitter in turn does not transmit an identification.
It is most particularly advantageous if the transmitter device is a passive transmitter device which can be activated by a receiver. As a result, the code carrier device does not have to be provided with a separate electrical supply. The code carrier device can then be mounted on a material flow object without supply lines or the like having to be provided.
In particular, the code carrier can in this case be supplied with energy via an electromagnetic field coupled in by a receiver. In particular, the receiver permanently emits an electromagnetic field with a specific frequency, for example 100 kHz, of a specific power and with a specific radiation characteristic. Once a specific relative positional range between the receiver and code carrier device has been reached, currents are inductively induced in the coils there, and a capacitor which supplies the energy for operating the electrical circuits of the code carrier device is charged. The code word stored in the memory can then be read and a corresponding modulated signal provided, which signal is in turn radiated via the coil, which is now acting as a transmitter, and is registered by the receiver.
It may be provided that the code carrier stores an unalterable identification. It is advantageous if the code carrier can be written by means of a receiver, reading of the identification and writing of a new identification taking place in particular in different frequency ranges.
In the case of writing by a receiver (writing coil), a transmitting face of the code carrier device provides a receiving face for the writing signals for writing on the code carrier.
In the case of a variant of an embodiment, a first transmitting face, a second transmitting face and a third transmitting face, which respectively are transversely in relation to one another, are provided. This allows the identification to be read when the material flow object is moved in three different directions of movement, lying transversely in relation to one another, with the receivers correspondingly positioned.
In particular, a housing of the code carrier device is in such a way and the transmitting areas are oriented in such a way that the latter lie substantially in the possible directions of movement of the material flow object. This allows the identification to be read in each direction of movement of the material flow objectxe2x80x94with correspondingly positioned receivers (reading head coils).
The following description of preferred embodiments serves in conjunction with the drawing for a more detailed explanation of the invention.